Abstract

nanocrystals are grown in silica starting from a sol-gel method and using Er doping to passivate the cluster boundaries. As a result, emission at from the decay of free excitons is observed in nanostructured , besides the extrinsic luminescence of defects in and ascribable to substoichiometric nanocluster boundaries. The analysis of the extrinsic emission competitive with the ultraviolet (UV)luminescence evidences the involvement of a phonon mode at from a SnO-like phase. The feasibility of passivated wide-band-gap nanocrystals in silica gives interesting perspectives for UV-emitting optical devices.